With the first challenge in 1870 by the British, the NYCC was able to defend the Cup successfully in 24 races. Defender and challenger sailed with magnificent yachts which were financed by syndicates of the then most powerful industrialists. They developed various powerful boat classes. The last one was the already smaller, but still expensive J-Class. The "Endeavour II" fought in the AC 1937 with "Ranger" to the last time.The Second World War (1939-45) broke the America's Cup until 1958. A change of the "Deed of Gift" reducing the minimum waterline from 90 to 44 feet enabled the introduction of the already successful 12-m class. But the 90 feet were not deleted and interpreted later on as maximum length (see AC 1988)

The 12ms sailed in 10 Cups (1958, 1962, 1964, 1967, 1970, 1974, 1977, 1980, 1983 and 1987) 1983 was the year in which the New York Yacht Club, resp.. the United States lost after 132 years for the first time the America's Cup's to a challenger, in this case to the Australian Royal Perth YC with its Australia II